“When we took office, let me remind you, there was virtually no international pressure on Iran. We were the problem,” Mr. Biden said. “We were diplomatically isolated in the world, in the region, in Europe.”

Lanhee Chen, policy director for the Romney campaign, quickly pounced on Mr. Biden’s remark with a statement calling it “reckless” and “a new low” for the Obama administration.

Mr. Chen went on to explain what he thinks the real issues are in Iran and why he thinks President Obama’s approach to the Iranian regime is “naïve.”

“The problem is not America. It is the ayatollahs who oppress their people, threaten their neighbors, and are pursuing nuclear weapons,” Mr. Chen said. “President Obama’s naïve approach to Iran has given the regime valuable time to get closer than ever before to a nuclear weapons capability. Vice President Biden’s comments are wrong and completely inappropriate.”

Mr. Chen ended his statement by promising Mr. Romney will take a tougher tack with respect to Iran.

“Mitt Romney will stand up for America and our allies, and he will not apologize for America’s leadership role in the world,” he said.